Idiopathic pulmonary fibrosis

Question 1

Define idiopathic pulmonary fibrosis

Answer 1

Inflammatory condition of the lung resulting in fibrosis of the alveoli and interstitium. AKA cryptogenic fibrosing alveolitis.

Question 2

Explain the aetiology/ risk factors of idiopathic pulmonary fibrosis

Answer 2

Occurs in genetically predisposed individuals

Reccurent injury to alveolar epithelium →secretion of cytokines and GFs → fibroblasts are recruited, proliferate and diff into myofibroblasts →collagen deposition

Certain drugs can cause this: methortrexate and amiodarone

Risk factors:

• Smoker
• Male
• Occupational exposure to dusts, metal, wood, pain
• Chronic microaspiration (Neurodeg, CVD, sleep)

Question 3

Summarise the epidemiology of idiopathic pulmonary fibrosis

Answer 3

RARE
0.006%

M:F 2:1

Associated with other AI diseases

Middle age

Question 4

Recognise the presenting symptoms of idiopathic pulmonary fibrosis

Answer 4

Gradual onset SOBOE

Dry irritating cough

NO WHEEZE
Might precede viral-type illness

Fatigue, WT

Question 5

Recognise the presenting signs of idiopathic pulmonary fibrosis

Answer 5

Clubbing 50%

Bibasal fine late inspiratory crackles

Signs of RHF in advanced stages (oedema, SOB, arrhythmias, cough with pink frothy sputum)

Question 6

Identify the appropriate investigations for idiopathic pulmonary fibrosis

Answer 6

Bloods:

• ABG: normal in early, PO2 decreases with ex, PCO2 rises in late stages
• ANA and RF: normal or mildly elevated

CXR:

• normal at presentation
• basilar, peripheral, bilateral, asymmetrical, reticular opacities

HRCT: early: ground-glass appearance, late: reticulonodular shadow, cor pulmonale, honeycombing

Pulmonary fx tests: restrictive, low FEV1, FVC or same or high ratio, low volumes, compliance and capacity

BAL: exclude infection/ malignancy

Biopsy: GOLD STANDARD - scar, fibrosis, inflam, honeycomb

Echo: check for RHF, pulmonary HTN.